In a randomized, double-blind, cross-over trial, 48 patients scheduled for total knee arthroplasty with placement of an intracapsular catheter will be randomized to receive bolus injection of ropivacaine in high volume/low concentration (20 ml, 5 mg/mL) or low volume/high concentration (10 mL, 10 mg/mL) 6 and 24 hours postoperatively, and pain will be assessed at rest and with mobilization for 2 hours after injections.